The present invention relates to a method of fabricating a semiconductor device in general and in particular to a method of using photon radiation in conjunction with an anti-reflective coating for annealing an ion implanted semiconductor device and products and apparatus made therefrom.
In recent years it has been demonstrated that continuous wave (CW) laser annealing can activate high dose implants in silicon with no deviation from the implanted impurity profile. See, A. Gat and J. F. Gibbons, "A Laser-scanning Apparatus for Annealing of Ion Implantation Damage in Semiconductor," Appl. Phys. Let. 32(3), P142, February 1978. It has also been demonstrated that it can also reduce polysilicon sheet resistance. See, A. Gat, L. Gerzberg, J. F. Gibbons, T. J. Magee, J. Peng, J. D. Hong, "CW Laser Anneal of Polycrystalline Silicon: Crystalline Structure, Electrical Properties," Appl. Phys. Lett. 33(8), p775, October 1978. Because of these features, CW laser annealing is an attractive processing technology for fabricating VLSI circuits. Heretofore, however, these potential advantages have not been demonstrated by improvement in the dynamic behavior of a circuit.
In the past the primary difficulty with the CW laser annealing process was that regions covered with SiO.sub.2 layers absorbed more energy than the implanted source and drain areas. This was due to the interference affect of the coherent laser light. This caused excessive heating in the junction parameter area which induced defects and yielded poor device characteristics. See, A. Gat, et al., Appl. Phys. Lett. 33(8) p775, October 1978, supra, and T. C. Teng, J. D. Merritt, J. Velez, J. Peng, L. Palkuti, "Short-Channel Polysilicon-Gate MOSFET's Fabricated by CW Argon Laser Annealing of Arsenic Implanted Source and Drain," Electronics Letters, 16(12), June, 1980. Among the poor device characteristics obtained due to the excessive heating in the junction parameter area is the relatively high reverse bias voltage leakage current that occurs in the presence of such defects.